How to make a timer and when the timer is up than a barrier opens

Just use a lifecycle wired to a repeater wired to the barrier.

Welcome to the forum, @HELp1! Check out the new-user-must-read and forum-tips for more easy help! Read the Community Guidelines for a gist of the rules. If you ever run into a hard problem, just ask away! After all, this is a community forum!

Remember to mark a solution to avoid clutter!